6621669 has 10 divisors (see below), whose sum is σ = 9891750. Its totient is φ = 4414392.

The previous prime is 6621649. The next prime is 6621691. The reversal of 6621669 is 9661266.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 3849444 + 2772225 = 1962^2 + 1665^2 .

It is not a de Polignac number, because 6621669 - 2⁸ = 6621413 is a prime.

It is a super-2 number, since 2×6621669² = 87693000691122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6621649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 40794 + ... + 40955.

It is an arithmetic number, because the mean of its divisors is an integer number (989175).

Almost surely, 2^6621669 is an apocalyptic number.

It is an amenable number.

6621669 is a deficient number, since it is larger than the sum of its proper divisors (3270081).

6621669 is an equidigital number, since it uses as much as digits as its factorization.

6621669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81761 (or 81752 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 6621669 is about 2573.2603832492. The cubic root of 6621669 is about 187.7828052319.

The spelling of 6621669 in words is "six million, six hundred twenty-one thousand, six hundred sixty-nine".